Apple is sold an unprecedented 75 million iPhones and iPads in the last three months of 2012, earning the tech giant $54.4 billion (£34.4 billion) in revenue - but rises in lower-cost device sales and the cost of producing the iPhone 5 saw profits flatline to $13.1 billion (£8.3 billion).

What do publishers need to know? That - partly due to high demand for the cheaper iPad mini which Apple could not meet and the continuing sale of older iPhone models - Apple products are filtering down to more people on middling incomes.